The closed environment of a vehicle interior, whether it be a car, plane, train, etc., poses a great challenge in temperature control and personal comfort of the occupants. In hot climates the interior ambient of an unconditioned vehicle can reach temperatures well over 100 Fahrenheit. Even on mildly warm days, when the car is exposed to direct sunlight, the temperature of a vehicle cab can rise to very uncomfortable levels. Under these conditions there is a great need for an air conditioning system to cool the air and improve the personal comfort of the driver or passenger in the vehicle.
The conventional method used today to cool the interior compartment of a transportation vehicle is a mechanical air conditioning system. By this means, a refrigerant is compressed, condensed, expanded and evaporated to produce a cooling effect. It is widely used and it is a well established system. It requires large, heavy mechanical components and can produce a large amount of cooling with a likewise large amount of energy consumption. The system is designed to cool the entire cab of the vehicle.
Common in aircraft is a compressed air system. In this system air is compressed and expanded to create a cooling effect. Components are large and heavy and create a large amount of cooling at the cost of high energy consumption.
These large systems drain the engine of performance and reduces the gas mileage by as much as 20%. They are inefficient in the sense that they cool the entire interior space, resulting in cool areas where no occupant is present.
There are a number of reasons why a vehicle may be manufactured without an air conditioning system. Weight limitation, as with electric cars, small airplanes or helicopters, will restrict the use of heavy components of a mechanical system. Another reason may be the high cost of installation and components of a mechanical air conditioning system. Still another reason may be space restrictions. Mechanical air conditioning systems have many moving parts that are susceptible to failure. Refrigerant leakage through the hoses and broken belts are likely. They must be properly adjusted to run efficiently and break down is common if not inevitable. In addition, the mechanical air conditioning system that runs on yesterdays CFC type refrigerants faces obsolescence. The 1987 Montreal protocol adopted by the United States and many other countries bans the production of the most common refrigerants.
The invention deals with the problem of how to relieve a person of the uncomfortable environment that a vehicle without air conditioning can create. Presently, a broken down mechanical air conditioning system would require one of two alternatives: repair the CFC system or retrofit for non-CFC refrigerant. Both alternatives can be costly. In addition, repairing a CFC system means dealing with tightening supplies and rising prices of reclaimed CFC's. Retrofitting a systems tends to reduce the performance and cooling capacity. Another approach, if available and feasible, is to install an aftermarket system in the vehicle. This would be a full mechanical non-CFC system designed specifically for that vehicle and would certainly provide the cooling requirements. However, with automobiles for example, one typically cannot justify the exorbitant cost associated with installation of an air conditioning system, especially when the cost is compared to the depreciated value of the vehicle. Furthermore, the typical short time period of vehicle ownership deters one from taking on this expense. Another available option to lessen the effect of the heat is to purchase any number of available fans that are available on the market today. These are small, axial type fans that are either battery operated or run off the vehicle power. Albeit this is a cheap solution, these fans do not produce any active cooling and they fall far short of an acceptable cooling method. Consequently, many vehicles on the road are running absent an air conditioning system.
Driving in a car without air conditioning on a hot summer day is a miserable situation experienced at least once by most people. This is were the idea for the invention originated. Desperate to find some relief from the heat, it became apparent that no device existed that would adequately solve the problem of overheated vehicle occupants. Some sort of cooling means that was small portable, lightweight, inexpensive and actually produced a real cooling effect was needed. However, nothing was available that completely satisfied this need.
The cooling effect of a small stream of cool air directed on the face and head of an occupant can significantly improve the comfort of the individual. This phenomenon is disclosed in U.S. Pat. No. 5,193,347. The cooling air need only be approximately 8 degrees Fahrenheit below ambient, and a flow rate of approximately 6 cfm. Taking advantage of this phenomenon and applying it to a vehicle, it becomes unnecessary to cool the entire cab and no net cooling is required; adequate heat relief relies on the efficiency of cooling only the space around the occupant. The invention described herein provides such a cooling capacity and satisfies the requirement for the device to be in dose proximity to the head and face of the occupant.